1. Field of the Invention
The invention relates to a heat charging apparatus for water reservoirs and boilers, and especially to a heat charging apparatus for water reservoirs and boilers in heating and warm water installations designed for keeping a selectable minimum temperature.
2. Background Information
A heat pump is designed for air/water, water/water or brine/water, and the conventional heat pumps of the size in question consist of the following elements. In a first conventional model, the heat pump aggregate is directly connected with a warm water-boiler and is either placed on the top or on the side thereof and is known under the designation "HP-Boiler". This design uses a heating spiral, which is directly immersed into the boiler and is connected with the heat pump on the outside thereof for hot water heating.
The disadvantage of this design is that it is not possible to arrange the water in temperature layers from the top to bottom, since the heat spiral does not allow such an arrangement for physical reasons. A further disadvantage of this design that in case of a break-down or a defect of the heat pump, a specialist in air-conditioning or heating is required because the knowledge needed for the repair exceeds that of an average apartment manager. Also, the repair is rather time consuming, so that high repair costs result. Furthermore, it is not possible to remove the problem by means of an exchange unit because such a replacement is too time consuming.
In a second conventional heat pump, the unit is an independent unit that is connected to the heat pump boiler by means of two metal hoses, i.e., one at the bottom and one at the top, whereby the pressure-controlled throttle valve regulates the water quantity and consequently the water temperature.
A disadvantage of this design resides with the fact that such heat pumps are relatively large and consequently need considerable space. Also, this design operates with the cooling means R22, so that the water in the boiler can not be heated up to 60.degree. C., but only up to 50.degree. C. A further important problem is the compensation of circulation losses at low costs by means of the heat pump, which is not possible with this design. Therefore, such losses in this embodiment can only be compensated by means of an electric escort heating that is rather expensive and uneconomical due to high power consumption.
A further disadvantage resides with the fact that such designs have to be assembled at the site where they are installed, thus leading to high installation costs. Also, the charging pump cannot simultaneously be used as circulation pump.
Heat pumps of the design described above are commercially available today and have a heat output limit of 2.5 kW and can consequently not be used for a complete heating system in larger apartment buildings.